I'm currently using the OpenELEC embedded XBMC distro with my HP Pavilion dv6 laptop (which is based on AMD Vision, so I'm using fglrx for video). It's hooked up to my Sony 1080p telly via HDMI.

Right now, the TV is showing images at 1366x768 (the same resolution as the laptop's built-in display). If I tell XBMC to up the resolution to 1920x1080, both displays go mad (picture goes out of bounds, etc), which I assume is X not being able to cope with one of the displays not being able to reach it.

Does anyone have any ideas what I could do to get video out only to the TV? The laptop will be tucked away in a corner so I will have no use for the inbuilt monitor; I just need 1080p out on the TV, no more, no less. If I recall correctly, OpenELEC picks the first display only, which might be useful.